/**
 * Copyright (c) 2011-2012, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.jfinal.render;

import java.io.IOException;
import java.io.PrintWriter;
import com.jfinal.util.json.JsonBuilder;

/**
 * JsonRender.
 */
@SuppressWarnings("serial")
class JsonRender extends Render {
	
	private static final String contentType = "application/json;charset=" + getEncoding();
	
	private String key;
	private Object value;
	private String[] attrs;
	
	private String jsonText;
	
	public JsonRender() {
		
	}
	
	public JsonRender(String key, Object value) {
		this.key = key;
		this.value = value;
	}
	
	public JsonRender(String[] attrs) {
		this.attrs = attrs;
	}
	
	public void render() {
		if (key != null)
			jsonText = JsonBuilder.buildJson(key, value);
		else if (attrs != null)
			jsonText = JsonBuilder.buildJson(request, attrs);
		else
			jsonText = JsonBuilder.buildJson(request);
		
		PrintWriter writer = null;
		try {
			response.setHeader("Pragma", "no-cache");
			response.setHeader("Cache-Control", "no-cache");
			response.setDateHeader("Expires", 0);
			
			response.setContentType(contentType);
			writer = response.getWriter();
	        writer.write(jsonText);
	        writer.flush();
		} catch (IOException e) {
			throw new RenderException(e);
		}
		finally {
			writer.close();
		}
	}
}











